A de novo interstitial deletion of chromosome 15 band q25 as revealed by FISH-technique

Clin Genet. 1996 Jun;49(6):303-5. doi: 10.1111/j.1399-0004.1996.tb03793.x.


We report a new chromosomal finding in a 20 month-old girl. The minor clinical features included: moderate mental retardation, microcephaly, mild hypotonia and hypertelorism. Initially, what appeared to be a terminal deletion of the long arm of one chromosome 15 [15q26-->qter] was determined to be an interstitial deletion involving band 15q25 as revealed by FISH-technique, showing the presence of intact telomeric hybridization signals. The cytogenetic diagnosis was thus modified to 46,XX, del (15) (pter-->q24::q26--> qter). Nevertheless, the function of the enzyme telomerase should not be ignored, as healing could occur following such terminal deletions. Consequently, it will remain a difficult task to distinguish terminal deletions from those that are interstitial.

Publication types

  • Case Reports

MeSH terms

  • Chromosome Banding
  • Chromosome Deletion*
  • Chromosomes, Human, Pair 15*
  • Developmental Disabilities / genetics
  • Female
  • Humans
  • In Situ Hybridization, Fluorescence
  • Infant
  • Karyotyping